diff --git a/.rubocop.yml b/.rubocop.yml
index 53ac189..ea22bff 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,4 +1,6 @@
 ---
+inherit_from: .rubocop_todo.yml
+
 # Managed by modulesync - DO NOT EDIT
 # https://voxpupuli.org/docs/updating-files-managed-with-modulesync/
 
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
new file mode 100644
index 0000000..b551bec
--- /dev/null
+++ b/.rubocop_todo.yml
@@ -0,0 +1,25 @@
+# This configuration was generated by
+# `rubocop --auto-gen-config --no-auto-gen-timestamp`
+# using RuboCop version 1.50.2.
+# The point is for the user to remove these configuration records
+# one by one as the offenses are removed from the code base.
+# Note that changes in the inspected code, or installation of new
+# versions of RuboCop, may require this file to be generated again.
+
+# Offense count: 16
+# Configuration parameters: .
+# SupportedStyles: have_received, receive
+RSpec/MessageSpies:
+  EnforcedStyle: receive
+
+# Offense count: 8
+RSpec/StubbedMock:
+  Exclude:
+    - 'spec/unit/provider/alternatives/chkconfig_spec.rb'
+    - 'spec/unit/provider/alternatives/dpkg_spec.rb'
+
+# Offense count: 8
+RSpec/SubjectStub:
+  Exclude:
+    - 'spec/unit/provider/alternatives/chkconfig_spec.rb'
+    - 'spec/unit/provider/alternatives/dpkg_spec.rb'
diff --git a/.sync.yml b/.sync.yml
index 872928e..130aaeb 100644
--- a/.sync.yml
+++ b/.sync.yml
@@ -3,9 +3,3 @@
   enabled_lint_checks:
     - parameter_documentation
     - parameter_types
-Gemfile:
-  optional:
-    ':test':
-      - gem: 'mocha'
-spec/spec_helper.rb:
-  mock_with: ':mocha'
diff --git a/Gemfile b/Gemfile
index b149e6c..ddd05cc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,6 @@ source ENV['GEM_SOURCE'] || 'https://rubygems.org'
 group :test do
   gem 'voxpupuli-test', '~> 11.0',  :require => false
   gem 'puppet_metadata', '~> 5.0',  :require => false
-  gem 'mocha',                      :require => false
 end
 
 group :development do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 3226b22..58c9b66 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -11,7 +11,6 @@
 
 RSpec.configure do |c|
   c.facterdb_string_keys = false
-  c.mock_with :mocha
 end
 
 add_mocked_facts!
diff --git a/spec/unit/provider/alternatives/chkconfig_spec.rb b/spec/unit/provider/alternatives/chkconfig_spec.rb
index b2cfd6d..f3cbc1f 100644
--- a/spec/unit/provider/alternatives/chkconfig_spec.rb
+++ b/spec/unit/provider/alternatives/chkconfig_spec.rb
@@ -24,9 +24,9 @@ def my_fixture_read(type, path)
 
   describe '.all' do
     it 'List all alternatives in folder /var/lib/alternatives' do
-      described_class.expects(:list_alternatives).returns my_fixture_alternatives
-      described_class.expects(:update).with('--display', 'sample').returns my_fixture_read('display', 'sample')
-      described_class.expects(:update).with('--display', 'testcmd').returns my_fixture_read('display', 'testcmd')
+      expect(described_class).to receive(:list_alternatives).and_return(my_fixture_alternatives)
+      expect(described_class).to receive(:update).with('--display', 'sample').and_return(my_fixture_read('display', 'sample'))
+      expect(described_class).to receive(:update).with('--display', 'testcmd').and_return(my_fixture_read('display', 'testcmd'))
       described_class.all
     end
 
@@ -34,9 +34,9 @@ def my_fixture_read(type, path)
       subject { described_class.all }
 
       before do
-        described_class.stubs(:list_alternatives).returns my_fixture_alternatives
-        described_class.stubs(:update).with('--display', 'sample').returns my_fixture_read('display', 'sample')
-        described_class.stubs(:update).with('--display', 'testcmd').returns my_fixture_read('display', 'testcmd')
+        allow(described_class).to receive(:list_alternatives).and_return(my_fixture_alternatives)
+        allow(described_class).to receive(:update).with('--display', 'sample').and_return(my_fixture_read('display', 'sample'))
+        allow(described_class).to receive(:update).with('--display', 'testcmd').and_return(my_fixture_read('display', 'testcmd'))
       end
 
       it { is_expected.to be_a Hash }
@@ -47,8 +47,9 @@ def my_fixture_read(type, path)
 
   describe '.instances' do
     it 'delegates to .all' do
-      described_class.expects(:all).returns(stub_selections)
-      described_class.expects(:new).twice.returns(stub)
+      stub_instance = instance_double(described_class)
+      expect(described_class).to receive(:all).and_return(stub_selections)
+      expect(described_class).to receive(:new).twice.and_return(stub_instance)
       described_class.instances
     end
   end
@@ -59,11 +60,11 @@ def my_fixture_read(type, path)
     let(:resource) { Puppet::Type.type(:alternatives).new(name: 'sample') }
 
     before do
-      Puppet::Type.type(:alternatives).stubs(:defaultprovider).returns described_class
-      described_class.stubs(:update).with('--display', 'sample').returns my_fixture_read('display', 'sample')
-      described_class.stubs(:update).with('--display', 'testcmd').returns my_fixture_read('display', 'testcmd')
+      allow(Puppet::Type.type(:alternatives)).to receive(:defaultprovider).and_return(described_class)
+      allow(described_class).to receive(:update).with('--display', 'sample').and_return(my_fixture_read('display', 'sample'))
+      allow(described_class).to receive(:update).with('--display', 'testcmd').and_return(my_fixture_read('display', 'testcmd'))
       resource.provider = subject
-      described_class.stubs(:all).returns(stub_selections)
+      allow(described_class).to receive(:all).and_return(stub_selections)
     end
 
     it '#path retrieves the path from class.all' do
@@ -71,18 +72,18 @@ def my_fixture_read(type, path)
     end
 
     it '#path= updates the path with alternatives --set' do
-      subject.expects(:update).with('--set', 'sample', '/opt/sample1')
+      expect(subject).to receive(:update).with('--set', 'sample', '/opt/sample1')
       subject.path = '/opt/sample1'
     end
 
     it '#mode=(:auto) calls alternatives --auto' do
-      subject.expects(:update).with('--auto', 'sample')
+      expect(subject).to receive(:update).with('--auto', 'sample')
       subject.mode = :auto
     end
 
     it '#mode=(:manual) calls alternatives --set with current value' do
-      subject.expects(:path).returns('/opt/sample2')
-      subject.expects(:update).with('--set', 'sample', '/opt/sample2')
+      expect(subject).to receive(:path).and_return('/opt/sample2')
+      expect(subject).to receive(:update).with('--set', 'sample', '/opt/sample2')
       subject.mode = :manual
     end
   end
diff --git a/spec/unit/provider/alternatives/dpkg_spec.rb b/spec/unit/provider/alternatives/dpkg_spec.rb
index 78877bb..ba4cac5 100644
--- a/spec/unit/provider/alternatives/dpkg_spec.rb
+++ b/spec/unit/provider/alternatives/dpkg_spec.rb
@@ -20,7 +20,7 @@ def my_fixture_read(path)
 
   describe '.all' do
     it 'calls update-alternatives --get-selections' do
-      described_class.expects(:update).with('--get-selections').returns my_fixture_read('get-selections')
+      expect(described_class).to receive(:update).with('--get-selections').and_return(my_fixture_read('get-selections'))
       described_class.all
     end
 
@@ -28,7 +28,7 @@ def my_fixture_read(path)
       subject { described_class.all }
 
       before do
-        described_class.stubs(:update).with('--get-selections').returns my_fixture_read('get-selections')
+        allow(described_class).to receive(:update).with('--get-selections').and_return(my_fixture_read('get-selections'))
       end
 
       it { is_expected.to be_a Hash }
@@ -39,8 +39,9 @@ def my_fixture_read(path)
 
   describe '.instances' do
     it 'delegates to .all' do
-      described_class.expects(:all).returns(stub_selections)
-      described_class.expects(:new).twice.returns(stub)
+      stub_instance = instance_double(described_class)
+      expect(described_class).to receive(:all).and_return(stub_selections)
+      expect(described_class).to receive(:new).twice.and_return(stub_instance)
       described_class.instances
     end
   end
@@ -51,9 +52,9 @@ def my_fixture_read(path)
     let(:resource) { Puppet::Type.type(:alternatives).new(name: 'editor') }
 
     before do
-      Puppet::Type.type(:alternatives).stubs(:defaultprovider).returns described_class
+      allow(Puppet::Type.type(:alternatives)).to receive(:defaultprovider).and_return(described_class)
       resource.provider = subject
-      described_class.stubs(:all).returns(stub_selections)
+      allow(described_class).to receive(:all).and_return(stub_selections)
     end
 
     it '#path retrieves the path from class.all' do
@@ -61,18 +62,18 @@ def my_fixture_read(path)
     end
 
     it '#path= updates the path with update-alternatives --set' do
-      subject.expects(:update).with('--set', 'editor', '/bin/nano')
+      expect(subject).to receive(:update).with('--set', 'editor', '/bin/nano')
       subject.path = '/bin/nano'
     end
 
     it '#mode=(:auto) calls update-alternatives --auto' do
-      subject.expects(:update).with('--auto', 'editor')
+      expect(subject).to receive(:update).with('--auto', 'editor')
       subject.mode = :auto
     end
 
     it '#mode=(:manual) calls update-alternatives --set with current value' do
-      subject.expects(:path).returns('/usr/bin/vim.tiny')
-      subject.expects(:update).with('--set', 'editor', '/usr/bin/vim.tiny')
+      expect(subject).to receive(:path).and_return('/usr/bin/vim.tiny')
+      expect(subject).to receive(:update).with('--set', 'editor', '/usr/bin/vim.tiny')
       subject.mode = :manual
     end
   end
diff --git a/spec/unit/type/alternatives_spec.rb b/spec/unit/type/alternatives_spec.rb
index 2fe23d3..7de55e2 100644
--- a/spec/unit/type/alternatives_spec.rb
+++ b/spec/unit/type/alternatives_spec.rb
@@ -6,7 +6,7 @@
   describe 'property `path`' do
     context 'on Debian systems' do
       before do
-        Facter.stubs(:value).with('os.family').returns('Debian')
+        allow(Facter).to receive(:value).with('os.family').and_return('Debian')
       end
 
       it 'passes validation with an absolute path' do
@@ -20,7 +20,7 @@
 
     context 'on RedHat systems' do
       before do
-        Facter.stubs(:value).with('os.family').returns('RedHat')
+        allow(Facter).to receive(:value).with('os.family').and_return('RedHat')
       end
 
       it 'passes validation with an absolute path' do